Geographical Variations Of Morphological Characters In Cricetulus Kamensis

Cricetulus kamensis belong to the Rodentia,Cricetidae,Cricetinae,Cricetulus.It is endemic specices of the Qinghai-Tibet Plateau.It is distributes vertically in mountain with coniferous forest which altitude is around 3000 m to cold desert region which altitude is around 5200 m,and its' typical habitat are the valley with river and brush with leguminous plants.Domestic and international studies on morphological changes in animal species are not rare,but few studies have been done on C.kamensis.We chose 11 sampling areas in Qinghai-Tibet Plateau and collected C.kamensis as the material.we used the method of geometric morphometrics and statistics to analyze the variation of body,organs and skull morphological to explore the geographical variations of morphological characters in C.kamensis,and studied the effect of environmental factors on variation of morphological.The main research results are as follows:1?The body length was significantly positively correlated with the longitude of C.kamensis.The relative tail length had a significant positive correlation with the longitude,the annual average relative humidity and the annual average temperature.The relative tail length was significantly negatively correlated with the annual sunlight percentage and the annual average wind speed.There had a significant negative correlation between the relative hind foot length and latitude,and there had a significant negative correlation between the relative ear length and latitude.2?The relative spleen weight was positively correlated with the annual average relative humidity,and negatively correlated with latitude.Besides,the relative lung weight was negatively correlated with the annual average wind speed.3?The three directions of skull in C.kamensis all showed very significant results in procrustes ANOVA.The morphological variation of dorsal skull was found in the nasal bone,the orbit and the back head of the C.kamensis.We found that the nasal bone shrank with the increase of latitudes and annual average precipitation,and the back head lengthened and narrowed with the increase of latitude and annual average precipitation.The nasal bone got longer with the increase of longitude and annual average temperature,and the back head widened with the increase of longitude and annual average temperature.The orbital and the back head lengthened with the increase of longitude,annual average precipitation and annual average temperature,and widened with the increase of altitude,annual sunlight percentage and annual average wind speed.The morphological variation of the lateral skull was found in the incisor,bulla and back head.We found that the lateral bulla of the C.kamensis were higher with the increase of annual average relative humidity and annual average air pressure,but lower with the increase of altitude and annual sunlight percentage.The lateral incisor of C.kamensis grew shorter with the increase of altitude and annual sunlight percentage,and grew taller with the increase of annual precipitation and annual average relative humidity.The height of the lateral back head of C.kamensis became higher with the increase of altitude and annual sunlight percentage,and decreased with the increase of annual average relative humidity and annual average precipitation.The morphological variation of the ventral skull was found in the zygomatic arch,palatine bone and foramen magnum.We found that the zygomatic arch shortened and flattened with the increase of latitude,annual average sunlight percentage,but lengthened and convexed with the increase of longitude,annual average relative humidity and temperature.the palatine bone shortened with the increase of longitude,latitude,annual average temperature and annual average air pressure,the palatine bone became smaller with the increase of longitude,latitude,annual average temperature and annual average air pressure.The foramen magnum had significant correlation with annual average wind speed,and had negatively correlation with latitude,longitude,annual average temperature.Mantel test showed that the morphological changes between the various of lateral and ventral of skull of C.kamensis were significant positive correlation with the geographical distance and genetic distance.4?ANOVA showed that different geographical populations of C.kamensis showed significant difference in the centroid size.We found that the centroid size of the C.kamensis increased with the increase of the longitude,the annual average relative humidity,but decreased with the increase of the altitude,the annual sunlight percentage and the annual average wind speed.In conclusion,there was a significant geographical morphological variation in C.kamensis population,we found that skull morphological variation mainly concentrated in the nasal bone,bullae,zygomatic arch and the back head.The tail length was significantly correlated with the most environmental factors,the reason was the characteristics can adapte to the morphology and function of tail.The visceral weight was not significantly related to the most environmental factors,C.kamensis had adapted to Qinghai-Tibet Plateau for a long time.This study can provide evidence for the effect of environment to animal phenotype.